Electric fire lighting apparatus



Oct- 1934- w. SCHOTTKY 1,977,151

'--1 ELECTRIC FIRE LIGHTING APPARATUS Filed Sept. 24. 1951 Patented Oct. 16, 1934 PATENT OFFICE ELECTRIC FIRE LIGHTING APPARATUS Walter Schottky, Berlin-Charlottenburg, Germany Application September 24, 1931, Serial No. 564,749 In Germany September 26, 1930 2 Claims.

My invention relates to an electric fire lighting apparatus, more particularly for domestic ovens or ranges.

My improved fire lighting apparatus consists 6 substantially of the combination of an air conveying device with an electric heating device. The air set in motion by the air conveying device and passing through the heating device is brought to such a high temperature that the combustible 10 material or fuel, against which the current of hot air is directed, is ignited or kindled. The device may, for instance, be so designed that in an apparatus constructed in the manner of the well known hot air hairdryers, viz. in the shape 16 of a gun, the heating element located in the tubular member or barrel being so dimensioned that the air set in motion by a fan is heated to a temperature of 800 C. The mouthpiece of the apparatus is, according to my invention, preferably 20 constructed of a refractory material, such as a ceramic material, and not of metal as customary heretofore.

In order that the velocity of the air should not become too great in the nozzle of the apparatus,

26 the tubular member may according to my invention be subdivided in such a manner, that it consists of a plurality of tubes arranged side by side and each of which contains an electric heating element. It appears, furthermore, advisable 30 to throttle the current of air produced by the fan to such an extent, or to choose from the beginning a fan of such small proportions that the volume of air set in motion by the fan amounts -to a fraction only of the air conveyed by the present hot air hairdryers. In order to obtain a particularly suitable construction of a bundle of tubes located side by side, the individual tubes may be of square or hexagonal cross-section and be arranged in the manner of honeycomb cells.

As it may happen that sometimes the heating element alone is connected in circuit and that for some reason or other the fan or blower does not become operative, the mouthpiece or barrel is according to another feature of my invention so dimensioned that it is not burned if there is no current of air.

An embodiment of my invention is by way of example illustrated, partly in sectional elevation, in the drawing affixed to my specification and forming part thereof.

On referring to the single figure of my drawing it will be seen that in a preferred construction my apparatus is similar in design to the customary hairdryer in the shape of a gun. i

In a housing or case 1 of metal or insulatin material there is accommodated an electrically driven fan. The housing is provided with a suitable handle 2 through which is passed the flexible connecting cord 3 by which the device is connected to a supply line. The apparatus is equipped with a fractional horsepower motor for driving the fan or air propeller and a switch, both well known and therefore not shown in the drawing. The housing is provided with a tubular extension 4 upon which is placed a mouthpiece, consisting of a metal sheath or envelope 5 enclosing a core 6 of refractory, more particularly ceramic insulating material. This insulating core 6 is provided with a plurality of channels or ducts 7 in which are contained heating elements 8 in the form of helical windings of wire. or the like.

' The air set in motion by the fan or blower and the temperature produced by the heating windings 8 are so proportioned that the current of air generated by the apparatus reaches a temperature sufficient for lighting, igniting or kindling combustible bodies or materials. If the current of hot air is then directed towards and made to impinge upon wood, paper, coal in the form of a briquet, and the like, this body is lighted or kindled merely by the heat carried along by the current of air.

Instead with a rotating fan, the electric heating element or member may equally well be combined with a blowing device of any other kind, as will be readily understood, and the element 1 of the drawing is intended to indicate any kind of blower device.

For instance, in view of the fact that only comparatively small quantities of air are necessary for attaining the end in view, so-called vibration blowers are also suitable for the purpose, i. e. air conveying apparatus in which a unidirectional current or flow of air is set up by a rapidly vibrating or oscillating diaphragm. The flow of air may also be set up merely by chimney or stack action. For this purpose the tube containing the heating member will preferably be arranged vertically and passed into the opening or door of the oven by a bend. As the temperature of the air impinging on the heating element is very high and the air expands to about thrice its volume a comparatively strong draft of air is generated which is in many cases sufficient to attain the object of my invention. My improved fire lighting apparatus may according to another feature of my invention be built into an oven or range in such a manner that the air discharge nozzle is from the beginning so directed that the hot air issuing from its impinges upon the material to be lighted in the manner desired. Such an apparatus may work in conjunction with a fan or without a fan, the necessary draft in the latter case being produced merely by chimney or stack ction. An oven or range equipped with such apparatus would then letaken into use in such a way that the fuel is suitably piled up in the doorway or furnace opening of the oven or range and the electric lighting apparatus is set in operation for a few minutes. As soon as the fuel has caught fire the lighting apparatus is switched off again. If the fire lighting apparatus is not arranged in the oven or range itself, it may according to another mode of use of my invention be combined with a structure or framework adapted to hold it in the correct position. Preferably a holding device may also be provided for the fuel to be ignited or kindled, for instance for the briquet to be lighted, and so arranged that the briquet is held at the correct distance from and position in front of the heating nozzle.

It will be readily understood that my improved apparatus may be utilized for other purposes in which it is necessary to heat a body. The apparatus may thus, for instance, be used as auxiliary means for forging or tempering iron or steel and the like, by directing the apparatus. which may be designed in the manner of a hairdryer or the like heating apparatus against the object or article to be heated. It will be understood that an existing compressed air pipe system may of course be utilized for the purpose of my invention. A special air blowing device or fan then becomes unnecessary, and the apparatus may then be designed in such a way that the tubular extension or barrel containing the heating device is merely connected to the existing compressed air mains by a suitable pipe. My improved apparatus may then be utilized for various industrial purposes in which it is necessary or desirable that a substance or material to be heated does not come in contact with an open flame or with products of combustion.

To prevent the apparatus from causing damage released. Devices of this kind are well known in the art, and therefore not illustrated in the present drawing.

It will be understood that structural changesand modifications may be made without departing from the spirit of my invention and the ambit of the appended claims.

I claim as my invention:

1. An electric fire lighting device, comprising a heating nozzle. of refractory insulating material divided into a. plurality of longitudinal air passages and individual'electric heating elements in said passages, a blower-forming the support for said nozzle and being connected to it to force a current of air through said passages whereby a definite direction is imparted to the air jet emanating from the nozzle, a casing surrounding said blower for supporting the entire structure, said heating elements being dimensioned as to their heat emission and with respect to the amount of air passing through said nozzle, to heat the air jet emanating from the nozzle to a temperature suflicient to ignite solid fuel.

2. An electric fire lighting device, comprising a heating nozzle of refractory insulating material divided lnto a plurality of longitudinal air passages and individual electric heating elements in said passages, a blower forming the support for said nozzle and being connected to it to force a current of air through said passages whereby a definite direction is imparted to the air jet emanating from the nozzle, a casing surrounding said blower and having a handle for supporting the entire structure, said heating elements being dimensioned as to their heat emission and with respect to the amount of air passing through said nozzle, to heat the air Jet emanating from the nozzle to a temperature sufllcient to'ignite solid fuel.

' WALTER SCHOTTKY. 

